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| -rw-r--r-- | guides/source/migrations.md | 22 |
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diff --git a/guides/source/migrations.md b/guides/source/migrations.md index 6742c05946..221251adf4 100644 --- a/guides/source/migrations.md +++ b/guides/source/migrations.md @@ -415,6 +415,28 @@ end removes the `description` and `name` columns, creates a `part_number` string column and adds an index on it. Finally it renames the `upccode` column. +### Changing Columns + +Like the `remove_column` and `add_column` Rails provides the `change_column`. + +```ruby +change_column :products, :part_number, :text +``` + +This changes the column part_number on products table to be a text. + +Besides the `change_column`, the `change_column_null` and +`change_column_default` are used specifically to change the null and default +values of a column. + +```ruby +change_column_null :products, :name, false +change_column_default :products, :approved, false +``` + +This sets name on products to a NOT NULL column and the default value +of approved as false. + ### When Helpers aren't Enough If the helpers provided by Active Record aren't enough you can use the `execute` |